1. Field of the Invention
This invention relates to instruments for performing medical examinations of the interior of the body. More particularly, this invention relates to improvements in electrical mapping of the heart using garments specially adapted to be worn on the surface of the body.
2. Description of the Related Art
The meanings of certain acronyms and abbreviations used herein are given in Table 1.
TABLE 1Acronyms and AbbreviationsECGElectrocardiogramACLActive Current Location
Methods are known for noninvasive mapping of electrical potentials in the heart based on body surface electrocardiographic (ECG) techniques. These methods combine 3-dimensional imaging with the ECG data in order to generate 3-dimensional maps of the electrical potentials on the epicardial surface, and on the endocardial surface, as well.
U.S. Pat. No. 7,983,743 to Rudy et al., which is herein incorporated by reference, proposes noninvasive systems and methods for determining electrical activity for a heart of a living being. A processor is configured to meshlessly compute data that represents heart electrical activity from a set of noninvasively measured body surface electrical potentials. This is accomplished using data that describes a geometric relationship between a plurality of locations corresponding to where the body surface electrical potentials were measured and the heart.
Reverse ECG mapping as, described in U.S. Pat. No. 7,983,743 attempts to generate an intracardiac ECG map by measuring body surface potentials at an array of positions on the skin of a patient. The method assumes that intracardiac ECG potentials {right arrow over (E)} generate body surface potentials {right arrow over (S)} and that the two sets of potentials are related by an equation of the form:{right arrow over (S)}=M·{right arrow over (E)}  (1),where M is a matrix, having elements mij.
The values of elements of the matrix M depend, inter alia, on the distance between the positions on the heart surface and the positions on the patient's skin, and on the conductivity of the material between these positions.
Commonly assigned U.S. Patent Application Publication No. 2008/0058657 by Schwartz et al., which is herein incorporated by reference, describes construction of a matrix relationship between a small number of endocardial points and a large number of external receiving points using a multi-electrode chest panel. Inversion of the matrix yields information allowing the endocardial map to be constructed.
Commonly assigned U.S. Patent Application Publication No. 2015/0133759 by Govari et al., which is herein incorporated by reference, describes a technique of injecting signals from an array of vest electrodes, and detecting them in a catheter positioned within the heart. A matrix is generated, inverted, and multiplied by subsequent vest electrode potentials to get heart potentials.